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WW HEADERS_END What mathematicians call the shape like a doughnut.

IMG:torus.png

The plural of Torus is Tori (a good scrabble word).

The Four Colour Theorem has its equivalent on the torus. Maps on the torus may require as many as, but never require more than, 7 colours. ---- * http://en.wikipedia.org/wiki/Torus * http://mathworld.wolfram.com/Torus.html